July 13 (Reuters) - Oil Search Ltd said on Monday it expects to record an impairment charge in its half-year results to reflect a drop in the value of some assets due to the possible long-term impact of current economic conditions and weak oil and gas outlook.

The Papua New Guinea-focused oil and gas company will record a non-cash, pre-tax charge of $360 million to $400 million, largely related to some PNG exploration licences, it said in a statement to the stock exchange. (Reporting by Rashmi Ashok in Bengaluru; Editing by Muralikumar Anantharaman)